Everything posted by deanslights
For me it is just starting. There I was happy with my static display when I discovered Planet Christmas. But Noooo I had to see mega trees, leaping arches, ferris wheels animated controllers etc. Now I wake up and have to check out this site whenever I have spare time. Now I can't even set up my display with out thinking about what I am going to do the next year. You people are all on my naughty list! Thanks Chuck!
I use spagheti noodles on mine. After all if a mega tree falls in a display and no one is around does it make a sound? Murphy's law for guying states that "The more complicated the guying needs to be so the tree won't fall, the probability there won't be any place to guy at all." All kidding aside I make a pretty good living at keeping H.V. lines from falling on the Cindy-Lou Whos of the world and I would recommend going out to 15' if possible. Your 340# is capable of supporting 113# with a 6' lead and a 15' attachment point(derating the guy by 90%) while at 15' it would be capable of supporting 216#. As was stated before, the angle the guy makes with the tree is important. The shorter guy leads also create more downward force at the pole which would explain why some trees would fail. In essence guy it someway but don't worry you are only buiding a 15' tree not the Eiffel tower. Anyway someone let me know if linguini works!
Since galvanized aircraft cable has a minimum breaking strenghth of 3,700# I am assuming that you are pulling your cable up to somewhat of that tension to eliminate the sag? Your point of attachment is still 40-45' in the air at the pulley. Running the cable throuh the pulley to the bottom of the tree will still create a downward stress at the point of attachment. Good luck keeping the 6" lag bolt from pulling out! If you still want to do this back up both ends on either side of your 200' span with the same 3/16" wire to some anchor attachment capable of supporting the equivalent strength.
2011 will be the first year of the installation of a mega tree in my display. I will be using 1-1/4" steel pipe 15'high and would not attempt to use PVC. Failure is defined as a complete collapse (think mega tree on the ground) due to either soil or pole failure, or distortions beyond acceptable limits (think appearance). Collapse is easily avoided by making sure that the pole ultimate strength is greater than the loads it must support.(think ice, wind, weight of lights). One can calculate the ultimate strength of either steel or PVC but I think it is obvious what the result will be. Mine will also be guyed. (yes they are guy wires not guide wires). While on the subject of guy wires keep the lead to height ratio at 1:1 if at all possible.(decreasing the L/H will increase the loading on each guy wire).